1. Field of the Invention
The present invention is directed to a converged in-building network. More particularly, the network described herein is a combined network solution to provide wired in-building telecommunications as well as an in-building wireless (IBW) network.
2. Background
Several hundred million multiple dwelling units (MDUs) exist globally, which are inhabited by about one third of the world's population. Due to the large concentration of tenants in one MDU, Fiber-to-the-X (“FTTX”) deployments to these structures are more cost effective to service providers than deployments to single-family homes. Connecting existing MDUs to the FTTX network can often be difficult. Challenges can include gaining building access, limited distribution space in riser closets, and space for cable routing and management. Specifically, FTTX deployments within existing structures make it difficult to route cables within the walls or floors, or above the ceiling from a central closet or stairwell, to each living unit.
Conventionally, a service provider installs an enclosure (also known as a fiber distribution terminal (FDT)) on each floor, or every few floors, of an MDU. The FDT connects the building riser cable to the horizontal drop cables which run to each living unit on a floor. Drop cables are spliced or otherwise connected to the riser cable in the FDT only as service is requested from a tenant in a living unit. These service installations require multiple reentries to the enclosure, putting at risk the security and disruption of service to other tenants on the floor. This process also increases the service provider's capital and operating costs, as this type of connection requires the use of an expensive fusion splice machine and highly skilled labor. Routing and splicing individual drop cables can take an excessive amount of time, delaying the number of subscribers a technician can activate in one day, reducing revenues for the service provider. Alternatively, service providers install home run cabling the full extended length from each living unit in an MDU directly to a fiber distribution hub (FDH) in the building vault, therefore encompassing both the horizontal and riser with a single extended drop cable. This approach creates several challenges, including the necessity of first installing a pathway to manage, protect and hide each of the multiple drop cables. This pathway often includes very large (e.g., 2 inch to 4 inch to 6 inch) pre-fabricated crown molding made of wood, composite, or plastic. Many of these pathways, over time, become congested and disorganized, increasing the risk of service disruption due to fiber bends and excessive re-entry.
Better wireless communication coverage is needed to provide the desired bandwidth to an increasing number of customers. Thus, in addition to new deployments of traditional, large “macro” cell sites, there is a need to expand the number of “micro” cell sites (sites within structures, such as office buildings, schools, hospitals, and residential units). In-Building Wireless (IBW) Distributed Antenna Systems (DASs) are utilized to improve wireless coverage within buildings and related structures. Conventional DASs use strategically placed antennas or leaky coaxial cable (leaky coax) throughout a building to accommodate radio frequency (RF) signals in the 300 MHz to 6 GHz frequency range. Conventional RF technologies include TDMA, CDMA, WCDMA, GSM, UMTS, PCS/cellular, iDEN, WiFi, and many others.
Outside the United States, carriers are required by law in some countries to extend wireless coverage inside buildings. In the United States, bandwidth demands and safety concerns will drive IBW applications, particularly as the world moves to current 4G architectures and beyond.
There are a number of known network architectures for distributing wireless communications inside a building. These architectures include choices of passive, active and hybrid systems. Active architectures generally include manipulated RF signals carried over fiber optic cables to remote electronic devices which reconstitute the RF signal and transmit/receive the signal. Passive architectures include components to radiate and receive signals, usually through discrete antennas or a punctured shield leaky coax network. Hybrid architectures include native RF signal carried optically to active signal distribution points which then feed multiple coaxial cables terminating in multiple transmit/receive antennas. Specific examples include analog/amplified RF, RoF (Radio over Fiber), fiber backhaul to pico and femto cells, and RoF vertical or riser distribution with an extensive passive coaxial distribution from a remote unit to the rest of the horizontal cabling (within a floor, for example). These conventional architectures can have limitations in terms of electronic complexity and expense, inability to easily add services, inability to support all combinations of services, distance limitations, or cumbersome installation requirements.
Conventional cabling for IBW applications includes RADIAFLEX™ cabling available from RFS (www.rfsworld.com), standard ½ inch coax for horizontal cabling, ⅞ inch coax for riser cabling, as well as standard optical fiber cabling for riser and horizontal distribution.
Physical and aesthetic challenges exist in providing IBW cabling for different wireless network architectures, especially in older buildings and structures. These challenges include gaining building access, limited distribution space in riser closets, and space for cable routing and management.